This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We are interested in using the microfocus beam technology available at BL12-2 to analyze diffraction quality from various crystalline samples of g protein coupled receptor-ligand complexes. Our crystals are extremely small, in many cases 20 microns or less in each dimension, and thus far we have only obtained quality data from such samples using mini-beam technology at APS of Argonne National Laboratory. We would begin our work on BL 12-2 by collecting data on an already solved structures so that we can compare the quality with that from other micro-focus/mini-beam sources. Provided that the samples diffract similarly we will then utilize BL 12-2 to collect new diffraction data on our g protein-coupled receptors and complexes, for the purpose of structure determination. At that time we will work to obtain data on new ligand complexes with already solved structures as well as data on receptors and complexes not yet structurally characterized.